It is believed that examples of known fuel injection systems can use two or more fuel rails to deliver fuel to fuel injectors. Fuel is supplied to each fuel rail separately. The fuel pressure in one fuel rail is believed to vary relative to the other fuel rail. Such variation is believed to include fuel pressure spikes caused by the fuel injection pulses and other factors. It is believed that causing each fuel rail to fluidly communicate with the other fuel rails by a crossover tube can reduce fuel pressure spikes in each fuel rail.
The crossover tube is believed to be connected at one point to a mount on an engine and to the fuel rails by rigid connections. Leaks are believed to develop at the rigid connections due to powertrain vibrations or through repeated disassemblies of the fuel rail or the crossover tube.
It is believed that examples of known fuel injections systems that use such rigid connections have a number of disadvantages. Such examples are believed to restrict rotational movements between the fuel rail and the crossover tube.
It is believed that examples of known fuel injection systems use metal type fuel rails and elastomer type crossover tubes. Such examples are believed to have a number of disadvantages including assembly processes that rely upon costly connectors, couplers or quick-connectors.
It is believed that other examples of known fuel injection systems require considerable rotational movement when connecting a cross-over tube to a fuel rail due to the limited amount of volume in an engine compartment of a vehicle. Such examples are believed to reduce manufacturing efficiency due to the need to ensure that the crossover tube is not twisted or pinched during assembly of the crossover tube and the fuel rail.
According to the present invention, a fuel rail system is provided for fuel injectors. The fuel rail system comprises at least one fuel rail having at least one boss portion disposed on at least one end of the at least one fuel rail, a cross-over tube proximate to the at least one fuel rail, the cross-over tube having a circumferential lip disposed proximate at least one end of the cross-over tube. A clip to couple the crossover tube to the at least one fuel rail. The clip cooperating with the lip to allow circumferential rotation of the crossover tube.
The present invention also provides for a retaining clip for use with a fuel rail. The retaining clip comprises an annular body extending along a longitudinal axis between a first end and a second end. The first end has an inner diameter different from the inner diameter of the second end. The annular body includes a first arcuate leg coupled to a second arcuate leg. A tab extends from one of the first and second arcuate legs at the first end, the tab having a plurality of serrations extending generally away from the longitudinal axis. An arm extends from the other of the first and second arcuate legs, the arm having another plurality of serrations extending generally towards the longitudinal axis. A cantilever arm extends over the tab, and at least one catch surface disposed on at least one of the first and second arcuate legs, the at least one catch surface located proximate the second end and extending generally between the first end and the second end.
The present invention further provides for a method of coupling and providing for relative rotation between a crossover tube and at least one fuel rail of a fuel injection system. The crossover tube having a circumferential lip at one end, the at least one fuel rail having at least one outwardly directed circumferential boss portion disposed at one end. The method comprises capturing the circumferential lip by a first arcuate and a second arcuate portions of an annular body, the first and second arcuate portions extending between a first end and a second end, coupling the first and second arcuate portions of the annular body by serrations located on the first and second arcuate portions; and securing the cross-over tube to at least one fuel rail by attachment of at least one projection of the annular body to the boss portion so that the crossover tube rotates relative to the at least one fuel rail.